Currently, the e-mail servers trying to deliver mail from stackexchange to my address appear to sit behind 69.59.196.221
:
Dec 18 21:33:56 avalon postfix/smtpd[1132]: NOQUEUE: reject: RCPT from unknown[69.59.196.221]: 450 4.7.1 Client host rejected: cannot find your hostname, [69.59.196.221]; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<mx-out.stackexchange.com>
As you can see, my mail server rejects this e-mail, since it cannot find the IP address 69.59.196.221
in the records for mx-out.stackexchange.com
, where it should be in every sane set-up (don’t claim to be A when A claims not to know you).
The actual records as available in the DNS at the moment:
$ dig -x 69.59.196.221 PTR +short
peak-colo-196-221.peak.org.
$ dig mx-out.stackexchange.com +short
72.51.63.225
64.34.119.225
Is it possible to fix this such that 69.59.196.221
is listed as one of the hostnames for mx-out.stackexchange.com
?